Abstract This application seeks continuation of funding for the Minority Populations Prevention Researcher Training (MPPRT) program. The MPPRT addresses the urgent needs for culturally-competent STI- prevention research in racial and ethnic minority communities by offering research education and mentoring for social and behavioral prevention scientists who have cultural expertise and are initiating innovative programs of research. This five-year project will provide educational, mentoring and technical assistance to facilitate the development and continuation of innovative STI/HIV-prevention research in racial and ethnic minority populations by expanding the currently successful program to: 1) Train MPPRT scientists in research methods (such as behavioral measurement, ethnography, GIS mapping, structural equation modeling, and social network analysis) to build scientists' capacity to conduct interdisciplinary STI/HIV-prevention research of structural and individual factors affecting STI/HIV-risk behavior in racial and ethnic minority populations; 2) Provide funding for pilot research that will yield preliminary data for multi-year grant proposals; 3) Provide education and mentoring in the writing and submission of multi- year grant proposals; and 4) Provide ongoing technical assistance and mentoring to MPPRT scientists to continue their programs of research to prevent STI/HIV in racial and ethnic minority populations. Aims 1, 2, and 3 will be met through an intensive six-week summer program of seminars and one-on-one meetings to be held at the UCSF Center for AIDS Prevention Studies as well as provision of funds to conduct a pilot research study. Beginning in the summer of 2009, two new scientists from U.S. universities and research institutions will be added to the program each summer in 2009, 2010, and 2011. These scientists will design pilot studies, which they will conduct during the following academic year, and return to CAPS for a second summer to analyze data from their pilot studies. In the third summer they will return to CAPS to write a larger grant proposal that will be submitted to a federal or non-federal agency. Aim 4 will be met by providing former scientists continued access to individualized advice and support from MPPRT mentors, including peer review and consultation regarding scientific questions related to the scientist's research program. The guidance provided by these collaborative research experiences and opportunities for interdisciplinary networking will result in a substantial increase in high quality STI-prevention research by scientists studying minority populations in the U.S.